Diurnal variation of phloem turgor pressure (A) and sap flow rate (B). Measurements were made in both foliation (Aug, 2011) and defoliation (Feb, 2012) seasons. The phloem turgor pressure and sap flow rate are simultaneously measured on four same trees. Sap flow rates were measured at 1.3 m height with a data log interval of 5 min while real-time phloem turgor pressures were determined at about 0.6 m height. Values shown are the means from four trees.